Protective helmet



FIG. 1 is a bottom plan view of a protective helmet showing my new design;

FIG. 2 is a left side elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a rear elevation view thereof; and,

FIG. 7 is a perspective view thereof.

My design includes a transparent screen, which can be pivoted from the lower position, shown in the above-referenced views, to an upper position, wherein the screen is positioned atop the upper surface of the helment. 

I claim the ornamental design for a protective helmet, as shown and described. 